The present invention relates generally to holographic display devices, and more particularly to extending projection boundaries of holographic display devices.
A hologram is a photographic recording of a light field, rather than of an image formed by a lens. Holograms can be displayed as a fully three-dimensional image of its subject matter, and this three-dimension image can typically be observed without the aid of special glasses or other intermediate optical equipment. Holograms typically include an encoded light field as an interference pattern of seemingly random variations in the opacity, density, or surface profile of the photographic medium. When correctly lit, the interference pattern diffracts the light into a reproduction of the original light field. In this way, objects that were in the original light field at the time the hologram was taken appear as three-dimensional images, and typically exhibit visual depth cues such as parallax and perspective that change realistically with any change in the relative position of the observer. Some forms of holography use laser light for illuminating the subject matter when the hologram is taken and also for viewing the hologram. Some holograms are entirely computer-generated and show objects or scenes that never existed.
Holography and other forms of making a three dimensional image will be collectively referred to herein as “three-dimensional imagery.” It is noted that “three-dimensional imagery,” as that term is used herein does not include imagery techniques where an image projected from, or onto, a two dimensional screen appears to be three dimensional.
As per recent technology, 3D holographic objects can be created in mid-air, as in the example shown in FIG. 1. A user can perform various interactions with the created 3D holographic objects. Holographic objects can be created by multiple holographic projectors coordinating with each other. Such a system will have a wide range area where a holographic object can be projected. Mobile devices are also capable of project holographic objects in the air, which limits the degree of freedom of the holographic projectors. Because the structure of the mobile device is fixed, holographic objects are created within a defined volumetric space, even with various combinations of micro-lens configurations.
Microfluidic lenses (sometimes herein referred to as “microfluidic layers”) are known. Microfluidic lenses can be dynamically adjusted with respect to their optical characteristics (for example, zoom or focal length).